Hvac system damper

ABSTRACT

A damper for determining and regulating amount of airflow admitted into a heating, ventilation, and air conditioning (HVAC) duct of a building from the ambient includes a variable position gate. The gate is configured to generate a continuous access opening into the duct from the ambient. The damper also includes a mechanism configured to select a position for the gate between and inclusive of fully opened and fully closed and a first sensor configured to sense a velocity of the airflow admitted into the duct. The selected position of the gate determines an area of the continuous access opening and regulates the amount of airflow admitted into the duct. Additionally, when the continuous access opening is not fully closed, the airflow admitted into the duct by the gate is substantially uniform. An HVAC system employing the damper and a method for controlling a temperature inside the building are also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 61/449,186 filed on Mar. 4, 2011, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The disclosure relates to a damper for determining and regulating airflow in heating, ventilation, and air conditioning (HVAC) systems.

BACKGROUND

A typical building employs a heating, ventilation, and air conditioning (HVAC) system for controlling temperature inside the building structure. Often such HVAC systems employ forced or pressurized air for distributing temperature-controlled air throughout the interior of the subject building structure.

A typical forced air system uses a damper in the form of louvered shutters at the location where the airflow enters the building structure from the ambient. Such a louvered shutter is intended to regulate the amount of airflow that is admitted into the structure and passed through either a heating or an air conditioning unit before being distributed throughout the interior of the building. The heating and air conditioning units are typically fan-assisted, and are thus employed as the mechanism behind the forced distribution of temperature-controlled air inside the building.

A large part of the energy used to cool or heat the building interior is spent for conditioning an airflow that is admitted into the building from the ambient. The amount of energy used to condition the ambient airflow is generally proportional to the amount of such airflow. Accordingly, efficient consumption of energy for controlling temperature inside a building is dependent on an accurate determination of the amount of ambient airflow being admitted into the building.

SUMMARY

A damper for determining and regulating amount of airflow admitted into a heating, ventilation, and air conditioning (HVAC) system of a building from the ambient includes a variable position gate. The gate is configured to generate a continuous access opening into the HVAC system from the ambient. The damper also includes a mechanism configured to select a position for the gate between and inclusive of fully opened and fully closed. The damper additionally includes a first sensor positioned relative to the continuous access opening and configured to sense a velocity of the airflow admitted into the duct. The selected position of the gate determines an area of the continuous access opening and regulates the amount of airflow admitted into the HVAC system. Additionally, when the continuous access opening is not fully closed, the airflow admitted into the HVAC system by the gate is substantially uniform or laminar.

The damper may also include a second sensor configured to sense a position of the gate and a controller. In such a case, the controller may be configured to regulate the mechanism in response to the sensed velocity of the airflow admitted into the HVAC duct and the sensed position of the gate to control the amount of airflow admitted into the duct.

The gate may be configured as first and second opposing panels, wherein each panel is characterized by a leading edge. Accordingly, the area of the continuous access opening may be adjusted by shifting at least one of the first and second panels via the mechanism between and inclusive of a state where the leading edges are abutted or brought together to select the fully opened position and a state where the leading edges are spread apart for a predetermined maximum distance to select the fully closed position.

The mechanism may include a motor operatively connected to a gear drive and the gear drive may be configured to shift at least one of the first and second panels.

The first panel may be configured to be shifted via the mechanism and guided by a track while the second panel is stationary. Additionally, both first and second panels may be configured to be shifted via the mechanism and guided by a track. Accordingly, the area of the continuous access opening may be adjusted by shifting one or both of the panels via the mechanism.

Each panel may be characterized by a flexible structure. Alternatively, each panel may also be configured from a plurality of segments.

Also disclosed is an HVAC system employing the damper for controlling a temperature inside the building. The HVAC system includes a duct configured to channel the airflow into the building, a heating unit and a cooling unit, each positioned inside the duct and configured to adjust temperature of the airflow channeled into the building. The HVAC system also includes a fan positioned inside the duct downstream of the heating and cooling units and configured to pressurize the airflow. Additionally, the HVAC system includes a controller configured to regulate the heating and cooling units, the fan, and the mechanism to control temperature inside the building.

Additionally disclosed is a method of controlling a temperature inside a building.

The above features and advantages, and other features and advantages of the present disclosure, will be readily apparent from the following detailed description of the embodiment(s) and best mode(s) for carrying out the described invention when taken in connection with the accompanying drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a building having a first embodiment of a heating, ventilation, and air conditioning (HVAC) system using a single damper.

FIG. 2 is a schematic illustration of a building having a second embodiment of a heating, ventilation, and air conditioning (HVAC) system using multiple dampers.

FIG. 3 is a schematic illustration of one embodiment of the damper shown in FIGS. 1 and 2.

FIG. 4 is a schematic illustration of an alternative embodiment of the dampers shown in FIGS. 1 and 2.

FIG. 5 is a flow chart illustrating a method of controlling temperature inside the building depicted in FIG. 1 via the damper.

DETAILED DESCRIPTION

Referring to the drawings, wherein like reference numbers refer to like components, FIG. 1 shows a cross-section of a building 10. The building 10 includes a building exterior 12 and a building interior 14. The building 10 employs a heating, ventilation, and air conditioning (HVAC) system 16 for controlling temperature inside the building, i.e., throughout the interior 14. The HVAC system 16 includes a duct 18 for receiving air from the ambient and then channeling and distributing an airflow 20 that is generated by the HVAC system throughout the interior 14. As shown in FIG. 1, the duct 18 includes a housing 22 that may include one or more filters 23 configured to remove dust and debris from the airflow 20.

As shown in FIG. 1, the housing 22 includes a heating unit 26, which may be configured as a heating coil, and a cooling unit 28, which may be configured as a cooling coil. The heating unit 26 and the cooling unit 28 are each positioned inside the duct 18, and are together configured to adjust temperature of the airflow 20 channeled the interior 14. The heating and cooling units 26, 28 may be configured as separate units or be combined into a single module. As shown, the HVAC system 16 also includes a fan 30 positioned inside the housing 22 downstream of the heating and cooling units 26, 28. The fan 30 is configured to force the airflow 20 through the duct 18 following the adjustment of the airflow temperature by either the heating unit 26 or the cooling unit 28.

The HVAC system 16 also includes a damper 32 positioned relative to the duct 18 upstream of the heating and cooling units 26, 28. The damper 32 is configured to regulate an amount of the airflow 20 admitted into the duct 18 (shown in FIGS. 1 and 2) from the ambient. As shown in FIG. 3, the damper 32 includes a variable position gate 34 configured to generate a continuous access opening 36 into the duct 18 from the ambient. Furthermore, a selected position of the gate 34 serves to adjust and determine an effective area 38 of the continuous access opening 36 to regulate the amount of the airflow 20 being admitted into the duct 18. The damper 32 also includes a mechanism 40 configured to select a position for the gate 34 between and inclusive of fully opened and fully closed. The access opening 36 is termed “continuous” because when the gate 34 is not fully closed the area 38 is unobstructed by any feature of the gate or its mechanism 40.

With continued reference to FIG. 3, the gate 34 includes opposing first and second panels 42, 44. The first panel 42 and second panel 44 oppose each other such that the gate 34 is operable between and inclusive of a fully opened and a fully closed state. The first panel 42 is characterized by a leading edge 46, while the second panel 44 is characterized by a leading edge 48. The area 38 of the continuous access opening 36 is adjusted by shifting at least one of the first and second panels 42, 44 via the mechanism 40. As shown, the mechanism 40 shifts both first and second panels 42, 44 between and inclusive of a state where the leading edges 46, 48 are abutted or brought together to select the fully opened position and a state where the edges are spread apart for a predetermined maximum distance to select the fully closed position of the gate 34. In any position of the gate 34 when the continuous access opening 36 is not fully closed, some airflow 20 is admitted into the duct 18. As a result of the access opening 36 being continuous, the airflow 20 that is admitted into the duct 18 by the gate 34 is not turbulent and is substantially smooth or laminar.

Although, as shown in FIG. 3, both of the first and second panels 42, 44 are actuated by the mechanism 40, the gate 34 may also be configured such that only one of the first and second panels needs to be moved while the other of the two panels remains stationary. Accordingly, if the mechanism 40 is configured to actuate both first and second panels 42, 44, the mechanism may include either a single motor 49 operatively connected to drive both panels (as shown in FIG. 3), or one motor per panel. On the other hand, if the mechanism 40 is configured to actuate only one of the first and second panels 42, 44, the mechanism 40 may include only one motor 49 operatively connected to drive the particular panel.

With continued reference to FIG. 3, the motor 49 is operatively connected to a gear drive 52. The gear drive 52 is configured to shift both the first and second panels 42, 44. The gear drive 52 is configured to actuate the first panel 42 directly. In the case depicted in FIG. 3, the second panel 44 is connected to the gear drive 52 via a motion-transmitting linkage 51, such that the first and second panels 42, 44 may be shifted substantially simultaneously by the motor 49. Accordingly, the motion-transmitting linkage 51 may be configured as any appropriate means, such as a chain (shown in FIGS. 3 and 4) or a belt (not shown), As additionally shown, the first and second panels 42, 44 are guided by a track 56 such that the first and second panels are consistently operated in a common plane. Therefore, the track 56 also facilitates full closure of the continuous access opening 36 to reduce leakage of air past the gate 34 when the leading edges 46, 48 are brought together.

As shown in FIG. 3, each of the first and second panels 42, 44 is configured from a plurality of individual segments 50. On the other hand, as shown in FIG. 4, each of the first and second panels 42, 44 may also be characterized by a flexible structure 53. The first and second panels 42, 44 may be configured from either individual segments 50 or be characterized by a flexible structure 53 such that the first and second panels may be either rolled up or folded when the gate 34 is being opened. Accordingly, either the individual segments 50 or the flexible structure 53 permit the gate 34 to occupy a reduced amount of space within the housing 22 as compared with a gate that employs rigid panels.

A traditional louvered shutter (not shown), as commonly used to control airflow in HVAC systems, employs a plurality of louvers that disrupt the airflow. As a result, such a louvered shutter generates a turbulent airflow whose velocity is difficult to measure by conventional velocity sensors or probes. Additionally, a louvered shutter typically generates a disproportionate amount of airflow in relation to the provided effective opening. As described herein, the variable position gate 34 is adapted to generate the continuous access opening 36 that admits a substantially laminar flow of air into the duct 18, as compared with the traditional louvered shutter. Additionally, as compared with the louvered shutter, the amount of the airflow 20 admitted through the gate 34 is directly proportional to the area 38. Accordingly, the gate 34 offers a more predictive means of controlling the amount of the airflow 20.

Referring back to FIG. 1, the building 10 additionally includes one or more return registers 54 that are mounted on the housing 22 upstream of the filters 23. The return registers 54 are configured to pull back into the housing 22 a portion of the previously adjusted temperature air as recirculation air from the interior 14. The recirculation air pulled back into the housing 22 by return registers 54 is mixed in with the newly admitted airflow 20, is subsequently forced through the filters 23 towards the heating and cooling units 26, 28. The building 10 also includes one or more exhaust fans 57. The exhaust fans 57 are configured to establish exhaust airflow from the interior 14 to the ambient. The actual number of exhaust fans 57 employed in a specific building is typically related to the physical area defined by the building's interior and the particular HVAC system design.

The HVAC system 16 also includes a controller 58. The controller 58 is configured to regulate the heating and cooling units 26, 28, the fan 30, and the mechanism 40 to determine the amount and control the temperature of the airflow 20 channeled into the building 10 by the duct 18. Accordingly, the controller 58 is configured to select the position of the gate 34 via the mechanism to adjust the area 38 of the continuous access opening 36. An appropriate position of the gate 34 may be selected by the controller 58 according to a programmed algorithm to thereby establish the desired amount of the airflow 20 admitted into the duct 18. After the desired amount of airflow 20 is admitted by the gate 34 into the duct 18, the airflow is passed through the heating and cooling units 26, 28 and then forced through the duct into the interior 14 by the fan 30. The controller 58 may be a separate controller incorporated into the damper 32, or be a central processing unit configured to control the HVAC system 16.

As indicated in FIGS. 3 and 4, the continuous access opening 36 is characterized by a height 60 and a width 62. The width 62 is a constant value that is defined by the width of the leading edges 46 and 48. At any particular instance, the position of the gate 34 selected by the controller 58 is known which allows the height 60 to be readily determined. Accordingly, the area 38 of the continuous access opening 36 at any particular timeframe may also be determined by multiplying the instantaneous height 60 by the width 62.

The HVAC system 16 also includes a first sensor 64 positioned relative to the continuous access opening 36 and a second sensor 65. The first sensor 64 is configured to sense a velocity of the airflow 20 and to communicate a signal indicative of the sensed velocity of the airflow to the controller 58. The first sensor 64 may be a single sensor positioned proximately to the center of the continuous access opening 36, or be configured as a sensor array capable of determining a velocity profile of the airflow 20. If the first sensor 64 is a sensor array, malfunction of an individual sensor may be detected using signals from the remaining sensors in the array, and the velocity profile may then be interpolated using the non-malfunctioning sensors.

The second sensor 65 is configured to sense a position of the gate 34 that is determinative of the area 38, and to communicate a signal indicative of the sensed position of the gate to the controller 58. The second sensor 65 may be configured as any appropriate device, such as a potentiometer or a switch, and be incorporated into the mechanism 40. The controller 58 is programmed to continuously determine a mass flow rate of the airflow 20 using the determined area 38 and the sensed velocity of the airflow 20.

As shown in FIG. 1, a temperature of the interior 14 may be sensed by a third sensor 66, which may feed the sensed data to the controller 58. Accordingly, in conjunction with the sensed temperature of the interior 14 by the third sensor 66, the determined mass flow rate of the airflow 20 may be used for controlling a temperature inside the building 10 by the controller 58. Accordingly, sensing the temperature of the interior 14 via the third sensor 66 and communicating a signal indicative of the sensed temperature by the third sensor to the controller 58 facilitates closed-loop temperature control of the building interior. Additionally, the determined mass flow rate of the airflow 20 provides a more direct means of controlling consumption of energy during heating and cooling of the building 10. The energy used for cooling and heating the building 10 may be regulated more precisely as a result of more predictive control of the amount of airflow 20 being admitted into the duct 18 through the continuous access opening 36.

FIG. 2 shows an alternative embodiment of the HVAC system 16. In FIG. 2, the HVAC system 16 employs two dampers 32. The housing 22 in FIG. 2 additionally includes a gas fired burner 24 configured to provide direct heating to the airflow 20 as the airflow enters the duct 18 through the damper. However, the housing 22 is devoid of the heating unit 26, which is replaced by the gas fired burner 24. As shown in FIG. 2, the airflow 20 enters the duct 18 from the ambient through two separate dampers 32. A first part 68 of the airflow 20 is pre-heated via the burner 24 when necessary in response to the sensed temperature of the interior 14, while the second part 69 of the airflow enters the duct 18 with its temperature unchanged. The first part 68 and the second part 69 of the airflow 20 are then recombined for subsequent distribution throughout the interior 14.

FIG. 5 depicts a method 70 of regulating controlling temperature inside the building 10 via the HVAC system 16 described above with respect to FIGS. 1-4. The method commences in frame 72 and then proceeds to frame 74 where the method includes adjusting the area 38 of the continuous access opening 36 into the duct 18 via the damper 32. As described above with respect to FIG. 3, the adjustment of the area 38 serves to regulate the amount of airflow 20 being admitted into the duct 18 from the ambient. Additionally, as described above, when the continuous access opening is not fully closed, the amount of the airflow 20 regulated by the gate 34 and admitted into the duct 18 is substantially laminar.

Following frame 74, the method advances to frame 76 where the method includes sensing the velocity of the airflow 20 admitted into the duct 18 via the first sensor 64. From frame 76, the method proceeds to frame 78, where the method includes sensing the position of the gate 34 via the second sensor 65. After frame 78, the method moves on to frame 80, where the method includes regulating the mechanism 40 using the sensed velocity of the airflow 20 and the sensed position of the gate 34 to adjust the area 38 of a continuous access opening 36. From frame 80, the method advances to frame 82. In frame 82, the method includes adjusting a temperature of the airflow 20 admitted into the duct 18 via the heating and cooling units 26, 28. Following frame 82, the method proceeds to frame 84. In frame 84, the method includes regulating the fan 30 to force the airflow 20 through the duct 18 in order to control the temperature inside the building 10.

The method may include determining the mass flow rate of the airflow 20. As described in detail with respect to FIG. 3, such determination of the mass flow rate of the airflow 20 is accomplished by the controller 58. Furthermore, such determination includes using the velocity of the airflow 20 sensed by the first sensor 64 in frame 76 and the area 38 of the continuous access opening 36 determined from the data gathered in frame 78 for controlling the temperature of the airflow. The method may also proceed from frame 84 to frame 86, where it includes sensing the temperature inside the building by the third sensor 66 and communicating a signal indicative of the sensed temperature to the controller 58 to generate closed-loop temperature control of the interior 14.

Following frame 86, the method may loop back to frame 74 to perform another adjustment of the gate 34 for regulating the amount of the airflow 20 flowing into the duct 18 in response to the temperature of the interior 14 sensed by the third sensor 66. Accordingly, the method may function continuously according to the preceding description while the temperature inside the building is sought to be controlled.

The detailed description and the drawings or figures are supportive and descriptive of the invention, but the scope of the invention is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed invention have been described in detail, various alternative designs and embodiments exist for practicing the invention defined in the appended claims. 

1. A damper for determining and regulating amount of airflow admitted into a heating, ventilation, and air conditioning (HVAC) duct of a building from the ambient, the damper comprising: a variable position gate configured to generate a continuous access opening into the duct from the ambient; a mechanism configured to select a position for the gate between and inclusive of fully opened and fully closed; and a first sensor positioned relative to the continuous access opening and configured to sense a velocity of the airflow admitted into the HVAC duct; wherein: the selected position of the gate is indicative of an area of the continuous access opening and determines the amount of airflow admitted into the duct; and when the continuous access opening is not fully closed, the airflow admitted into the duct by the gate is substantially uniform.
 2. The damper according to claim 1, further comprising a second sensor configured to sense a position of the gate and a controller configured to regulate the mechanism in response to the sensed velocity of the airflow admitted into the HVAC duct and the sensed position of the gate to control the amount of airflow admitted into the duct.
 3. The damper according to claim 1, wherein the gate is configured as first and second opposing panels, wherein each panel is characterized by a leading edge, and wherein the area of the continuous access opening is adjusted by shifting at least one of the first and second panels via the mechanism between and inclusive of a state where the leading edges are abutted to select the fully opened position and a state where the leading edges are spread apart for a predetermined maximum distance to select the fully closed position.
 4. The damper according to claim 3, wherein the at least one of the first and second panels is configured from a plurality of segments.
 5. The damper according to claim 3, wherein the at least one of the first and second panels is characterized by a flexible structure.
 6. The damper according to claim 3, wherein the mechanism includes a motor operatively connected to a gear drive, and wherein the gear drive is configured to shift the at least one of the first and second panels.
 7. The damper according to claim 3, wherein the first panel is configured to be shifted via the mechanism and guided by a track, and wherein the second panel is stationary.
 8. The damper according to claim 3, wherein each of the first and second panels is configured to be shifted via the mechanism and guided by a track.
 9. The damper according to claim 8, wherein the area of the continuous access opening is adjusted by shifting each of the first and second panels via the mechanism.
 10. A heating, ventilation, and air conditioning (HVAC) system for controlling a temperature inside a building, the system comprising: a duct configured to channel an airflow into the building; a heating unit and a cooling unit configured to adjust a temperature of the airflow channeled into the building, each positioned inside the duct; a fan positioned inside the duct downstream of the heating and cooling units and configured to force the airflow through the duct; a damper positioned relative to the duct upstream of the heating and cooling units and configured to regulate amount of the airflow admitted into the duct from the ambient, the damper comprising: a variable position gate configured to generate a continuous access opening into the duct from the ambient; a mechanism configured to select a position for the gate between and inclusive of fully opened and fully closed; a first sensor positioned relative to the continuous access opening and configured to sense a velocity of the airflow admitted into the duct; and a second sensor configured to sense a position of the gate; and a controller configured to regulate the heating unit and the cooling unit, the fan, and the mechanism to control the temperature inside the building in response to the sensed velocity of the airflow admitted into the duct and the sensed position of the gate; wherein: the selected position of the gate is indicative of an area of the continuous access opening and determines the amount of airflow admitted into the duct; and when the continuous access opening is not fully closed, the airflow admitted into the duct by the gate is substantially uniform.
 11. The HVAC system according to claim 10, wherein the gate is configured as first and second opposing panels, wherein each panel is characterized by a leading edge, and wherein the area of the continuous access opening is adjusted by shifting at least one of the first and second panels via the mechanism between and inclusive of a state where the leading edges are abutted to select the fully opened position and a state where the leading edges are spread apart for a predetermined maximum distance to select the fully closed position.
 12. The HVAC system according to claim 11, wherein the at least one of the first and second panels is configured from a plurality of segments.
 13. The HVAC system according to claim 11, wherein the at least one of the first and second panels is characterized by a flexible structure.
 14. The HVAC system according to claim 11, wherein the mechanism includes a motor operatively connected to a gear drive, and wherein the gear drive is configured to shift the at least one of the first and second panels.
 15. The HVAC system according to claim 11, wherein the first panel is configured to be shifted via the mechanism and guided by a track, and wherein the second panel is stationary.
 16. The HVAC system according to claim 11, wherein each of the first and second panels is configured to be shifted via the mechanism and guided by a track.
 17. The HVAC system according to claim 16, wherein the area of the continuous access opening is adjusted by shifting each of the first and second panels via the mechanism.
 18. The HVAC system according to claim 10, wherein the controller is programmed to determine a mass flow rate of the airflow admitted into the duct using the area of the continuous access opening and the velocity of the airflow to control the temperature inside the building.
 19. A method of controlling a temperature inside a building via a heating, ventilation, and air conditioning (HVAC) system, the method comprising: adjusting an area of a continuous access opening via a damper of the HVAC system to regulate an amount of airflow admitted from the ambient into a duct, wherein the duct is configured to channel the airflow into the building, wherein the damper includes a variable position gate configured to generate the continuous access opening into the duct from the ambient and a mechanism configured to select a position for the gate between and inclusive of fully opened and fully closed, and wherein when the continuous access opening is not fully closed, the amount of airflow regulated by the gate and admitted into the duct by the gate is substantially uniform; sensing a velocity of the airflow admitted into the duct via a first sensor positioned relative to the continuous access opening; sensing a position of the gate via a second sensor; regulating the mechanism using the sensed velocity of the airflow and the sensed position of the gate to adjust the area of a continuous access opening; adjusting, via heating and cooling units of the HVAC system, a temperature of the airflow admitted into the duct; and regulating a fan of the HVAC system positioned inside the duct downstream of the heating and cooling units to force the airflow through the duct and channel such that the temperature inside the building is controlled.
 20. The method according to claim 19, further comprising: determining the area of the continuous access opening in response to the sensed velocity of the airflow admitted into the HVAC duct and the sensed position of the gate to control the amount of airflow admitted into the duct; determining a mass flow rate of the airflow admitted into the duct using the area of the continuous access opening and the velocity of the airflow for controlling temperature of the airflow; and sensing the temperature inside the building by a third sensor and communicating a signal indicative of the sensed temperature to the controller to generate a closed-loop control of temperature inside the building; wherein each of said determining and adjusting the area of the continuous access opening via the damper, determining the mass flow rate of the airflow, adjusting temperature via the heating unit and cooling units, and regulating the fan is accomplished via the controller. 